From parakeets to Japanese knotweed, invasive non-native species are accused of harming our ‘native' wildlife. Environmental journalist Fred Pearce challenges this widespread view and asks whether demonising these species is justified by science. In the vast majority of cases these species are model ecological citizens and some of the perceived 'problem' species may even be the crucial first step towards repairing ecological damage caused by human actions and interventions. Maybe it is time we learnt to love this 'new wild'?